These stamps are visible to the end-user mail client and encode sender-specific information, the version of the spam filter definition file, Outlook puzzle validation results, and content filtering results.

• 这些标记对最终用户邮件客户端是可见的,并对发件人特定的信息、垃圾邮件筛选器定义文件版本、Outlook问题验证结果和内容筛选结果进行编码。